Sections

Liar, liar, diapers on fire: Study shows kids lie as young as two

Evian enjoyed a viral hit with its rollerskating babies ad, which caught viewers off-guard by showing youngsters performing an activity beyond their years. A new study on two-year-olds’ ability to spontaneously lie may inspire a similar reaction, as previous research suggested this behaviour didn’t start until a later age. Photo: YouTube

Misty Harris

Published: January 22, 2013 - 10:23 AM

Updated: January 22, 2013 - 11:32 AM

Groundbreaking new research confirms what parents have experienced firsthand for generations: that kids are capable of lying before they’re even out of diapers.

In the first study of its kind, investigators from two Canadian universities demonstrate that toddlers begin to tell verbal lies as young as two – about 18 months earlier than previous laboratory tests have shown. And the greater a child’s executive functioning – an umbrella term for reasoning, problem-solving, memory and other cognitive skills – the more likely they are to attempt deception.

In other words, researchers say lying by age two is actually an early developmental milestone.

“It’s not a sign your child is a sociopath,” said study co-author Kang Lee, a distinguished professor at the University of Toronto. “Lying just tells you that the child is getting to a new stage of cognitive development.”

The study, published in the journal Developmental Psychology, draws on experiments with 41 two-year-olds (average age 29.6 months) and 24 three-year-olds (average age 43.3 months) from Canadian households of diverse socioeconomic status.

After undergoing pre-tests to assess executive functioning, the children individually participated in a game in which they were asked to guess the identity of a hidden toy by the sound it made. A quack, for instance, would indicate a duck.

After two toys were successfully guessed, the adult leading the game excused herself under the guise of retrieving something from another part of the room. Before leaving, she instructed the child to keep his or her back turned to the next mystery toy.

Hidden cameras revealed that 80 per cent of the children peeked at the toy anyway. But when the adult later asked if they had looked, 40 per cent of the “peekers” fibbed about it.

In a surprise to researchers, fully a quarter of the two-year-old transgressors were in that group.

“Lying is quite a sophisticated skill,” said Lee, noting that it requires both executive functioning and theory of mind – that is, the ability to understand another person’s mental state. “It’s to know that what I know is something that you don’t know.”

The likelihood of peeking at the toy actually declined with age: for each month increase in age, the children were 1.12 times less likely to transgress. However, for those who did peek, the likelihood of lying about it increased with age and executive functioning: for each month increase in age, children were 1.14 times more likely to lie, and for each point increase in executive functioning score, they were more than five times likelier to lie.

“This helps us fill out the developmental picture,” said study co-author Angela Evans, assistant professor of psychology at Brock University.

For instance, they can now see the rate of lying after a transgression climbs from about 25 per cent among two-year-olds to 50 per cent among three-year-olds and 80 per cent among those four through 12. Then, at adolescence, it begins to decline, reaching 30 or 40 cent by about 16.

Taken another way, the findings suggest that if your toddler is always honest, it’s less likely the result of moral fortitude so much as an undeveloped ability to fib.

“Two-year-olds are generally honest,” said Evans. “But if yours is telling lies, it’s actually a good thing because it’s a sign that they’re developing cognitively.”